Conventional estimation apparatuses are known, which estimate the dynamics of a forward object using a state estimation filter, such as an alpha-beta (α-β) filter or a Kalman filter. Such an estimation apparatus sets, at the start of estimation, an initial value of a state quantity as the dynamic state of the state estimation filter according to observations associated with the dynamics of the forward object.
Note that the observations may have errors. An initial value, which greatly deviates from a real value, provided to the state estimation filter due to an error may result in the following problem. Specifically, great deviation of the initial value, which is based on state estimation, from the real value may make it difficult to estimate a state quantity with a high accuracy for a while after start of estimation by the estimation apparatus.
A technology to address the problem is known, which performs linear regression analysis of observations, and sets, at the start of estimation, an initial value for a state estimation filter according to the results of the linear regression analysis of observations (see patent document 1). This technology sets, as an initial value for the state estimation filter at the start of estimation, an initial position or an initial velocity of each of forward objects according to the results of execution of the linear regression analysis for the group of positions of the forward objects observed by a radar device.